How big is your solution?
Are the FileMaker Server computer a dedicated server without any other software on?
Have you disabled Anti Virus software to any FIleMaker Server folders, especially on live data folders?
Do you have Index on for folders where FileMaker Server runs?
What Windows Server are you using?
To get better performance FileMaker Server itself needs quite a lot of GB to store temporary data, but not that much as you have free.
Do you have all data on C: or have you data and backups on other hard drives?
I always install just OS on C:, have production data on D:, have backups on E: and then have Externally stored files on F: .
This will make me have a clean C: for only OS to run + FMS to work on and then I can easily keep track of free space on D:/E:/F: hard drives. Then I have a robot that moves backup (E:) to another place every night. I also take backups 6 times every day (8:00 AM, 10:00 AM, 12:00 AM, 2:00 PM, 4:00 PM and 6:00 PM). This backups I keep for one week before the override itself. Once every night at 01:00 AM I do a backup that verify my databases. This folder I also keep for one week. This make my environment safe is something where to go wrong.
Make sure you do not have Anti Virus running on the server. If you really need to, exclude folders where you keep your production databases.
If you have Index enabled on your Windows it will try to index your databases most and that can cause them to be corrupt.
I agree with all the advice given already and want to add that actual disk speed can be a factor as well. Not so much to cause an overnight backup to take hours. With a 180GB file you might want to consider more RAM. What do the stat logs show?
i would bet you have indexing on. It indexes your database and then tries to index the entire backup as well.
We've switched off indexing. We've ordered more RAM.
With the indexing off, the backup was still running this morning at 8am. So no difference there.
Will have to see what it does after we up the RAM.